Method for manufacturing an acoustic attenuation structure with control of the positioning of an acoustic skin

Abstract

A method for manufacturing an acoustic attenuation structure including the following steps: making a complex acoustic multi-element panel including a plurality of hollow complex acoustic elements and a plurality of partitions forming acoustic cavities, each complex acoustic element being housed in an acoustic cavity so as to form an acoustic cell, making a first skin, piercing a plurality of perforations on the first skin at determined locations to form a multi-perforated acoustic skin, assembling the complex acoustic multi-element panel with the multi-perforated acoustic skin. The multi-perforated acoustic skin including on its assembly face a plurality of positioning studs configured to cooperate with a hollow complex acoustic element or an acoustic cavity during the assembly of the complex acoustic multi-element panel with the multi-perforated acoustic skin.

1 . A method for manufacturing an acoustic attenuation structure comprising the following steps:
 making a complex acoustic multi-element panel comprising a plurality of hollow complex acoustic elements each having a shape gradually narrowing between a base and a top and a plurality of partitions forming acoustic cavities, each complex acoustic element being housed in an acoustic cavity so as to form an acoustic cell,   making a first skin,   piercing a plurality of perforations on the first skin at determined locations so as to form a multi-perforated acoustic skin,   assembling a face of the complex acoustic multi-element panel with an assembly face of the multi-perforated acoustic skin,   
       wherein the multi-perforated acoustic skin comprises on its assembly face a plurality of positioning studs present at determined locations, each positioning stud being configured to cooperate with a hollow complex acoustic element or an acoustic cavity during the assembly of the complex acoustic multi-element panel with the multi-perforated acoustic skin and in that one or several positioning studs have a shape complementary to the inner shape of the hollow complex acoustic elements. 
     
     
         2 . The method according to  claim 1 , wherein one or several positioning studs have a shape complementary to the shape of the acoustic cavities. 
     
     
         3 . The method according to  claim 1 , wherein the acoustic attenuation structure further comprises the assembly of the face of the complex acoustic multi-element panel opposite to the face covered by the multi-perforated acoustic skin with an assembly face of a closing skin. 
     
     
         4 . The method according to  claim 1 , wherein at least one positioning stud comprises a fixing member. 
     
     
         5 . The method according to  claim 1 , wherein the complex acoustic elements have a pyramidal, conical or spiral shape. 
     
     
         6 . The method according to  claim 1 , wherein at least the complex acoustic multi-element panel is made of a filled or unfilled thermoplastic or thermosetting material. 
     
     
         7 . The method according to  claim 6 , wherein at least the complex acoustic multi-element panel is made by injection of a filled or unfilled thermoplastic or thermosetting material. 
     
     
         8 . The method according to  claim 7 , wherein the complex acoustic multi-element panel and the plurality of partitions are made in a single piece by injection of a filled or unfilled thermoplastic or thermosetting material. 
     
     
         9 . The method according to  claim 1 , wherein each positioning stud is manufactured with the acoustic skin by thermoplastic stamping-overmolding or stamping with metal inserts. 
     
     
         10 . The method according to  claim 1 , wherein the positioning studs and the acoustic skin are made of a thermoplastic material, each positioning stud being added by welding or by bonding onto said skin. 
     
     
         11 . The method according to  claim 1 , wherein each positioning stud is made by additive manufacturing. 
     
     
         12 . An acoustic attenuation structure comprising:
 a complex acoustic multi-element panel comprising a plurality of hollow complex acoustic elements each having a shape gradually narrowing between a base and a top and a plurality of partitions forming acoustic cavities, each complex acoustic element being housed in an acoustic cavity so as to form an acoustic cell,   a multi-perforated acoustic skin comprising a plurality of perforations, said acoustic skin having an assembly face fixed on a face of the complex acoustic multi-element panel,   
       wherein the multi-perforated acoustic skin comprises on its assembly face a plurality of positioning studs present at determined locations, each positioning stud cooperating with a hollow complex acoustic element or an acoustic cavity of the complex acoustic multi-element panel and in that one or several positioning studs have a shape complementary to the inner shape of the hollow complex acoustic elements.